Interface for transcoding system

ABSTRACT

The invention relates to a transcoding system comprising an application platform and a transcoding platform for executing transcoding transactions that comprise the transmission of a request from the application platform to the transcoding platform, the execution of said request by said transcoding platform, and the transmission of a response to said application platform, said request and response having specific formats given in detailed tables. Moreover, the request has a transcoding parameter element comprising a transformation element that defines a transformation through which a content must go, amongst a plurality of supported transformations also defined in a detailed table.

FIELD OF THE INVENTION

The present invention relates to a transcoding system comprising anapplication platform and a transcoding platform for executingtranscoding transactions that comprise the following steps:

-   transmission of a request from said application platform to said    transcoding platform,-   execution of said request by said transcoding platform,-   transmission of a response from said transcoding platform to said    application platform.

In the present description, the word “platform” refers to a combinationof hardware and software that provides the functionality of theconcerned applications.

BACKGROUND OF THE INVENTION

The deployment of multimedia applications like MMS Multimedia MessagingService), WAP 2 (Wireless Application Protocol), e-mail, web browsing .. . etc.) may require some Content adaptations, due to the diversity ofthe phone specifications (memory, screen size, resolution, colour depth,etc, and supported media formats) and of the media formats asdistributed by the Content industry (JPEG, GIF, all AMR modes, 13Kvocoder, EVRC, SMV, MPEG-1, MPEG-4, H.263 . . . etc.). The word“Content” used here means any subject matter or information that isprocessed, stored or transmitted electronically. Content Adaptation islargely independent on the type of service that delivers the data to theend users. In this context, STI 1.0 is the first specification of astandard interface between the Multimedia Application Platforms and theTranscoding Platform and is meant to resolve some of the integration andtesting problems when deploying multimedia services towards mobiledevices.

SUMMARY OF THE INVENTION

The object of the invention is to propose a new solution for thestandard interface, to be used by OMA STI 1.0. (OMA=Open MobileAlliance).

To this end, the invention relates to a transcoding system such asdefined in the introductory paragraph of the description and in whichsaid request is based on a request body which is structured as indicatedin Table 1, and said response, when successful, is based on a responsebody which is structured as indicated in Table 3.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example, withreference to the accompanying drawings in which:

FIG. 1 illustrates a transcoding transaction;

FIG. 2 shows an overview of the request components for such atransaction;

FIG. 3 presents the transcoding job structure, including the sourceparameters and the target parameters,

FIG. 4 presents the response transaction structure, and

FIG. 5 presents the job result structure;

FIG. 6 is an example of combined media format;

FIG. 7 shows the structure of a request transaction, and

FIG. 8 the structure of a response transaction.

DETAILED DESCRIPTION OF THE INVENTION

A high level overview of the interaction between an Application Platform10 and a Transcoding Platform 20 is illustrated in FIG. 1. Thecommunication between the Platforms is transactional, that is atranscoding session is always a request 30 followed by a response 40. Asession is closed only when a response has been received. TheApplication Platform requests transcoding from the Transcoding Platform.The Transcoding Platform receives the request, parses it, handles it andgenerates a response to the originating Application Platform.

The choice of the protocol is done as follows. The interface betweenApplication Platform and the Transcoding Platform relies on a SOAPprotocol (SOAP v 1.1, http://www.w3.org/TR/SOAP/), sent over HTTP(HyperText Transfer Protocol) and used over TCP/IP (Transmission ControlProtocol/Internet Protocol).

FIG. 2 shows an overview of the request components. Multiple bulktranscoding within a single Request Transaction (=transcoding request,as issued by the Application Platform; it can contain one or moreTranscoding Jobs 1 to N and one or more Content Attachments 1 to M, aTranscoding Job being the part of the Request Transaction thatcorresponds to one individual transcoding, i.e. one input contentreference and the parameters corresponding to the particular transcodingas given by the Application Platform) is allowed by the proposedinterface: therefore one will distinguish between Transcoding Job(individual media transcoding) and Request Body (list of Job results)which can contain one or several Jobs as part of one single request tothe Transcoding Platform. For each single Transcoding Job within aRequest body, the transcoding parameters are specified within the SOAPcontext. In case a Transcoding Job contains the Content filesthemselves, they are attached inside the concerned message, but outsidethe SOAP envelope. Each Transcoding Job in a Request Body has to containthe source parameters (format, type, location, etc) and the targetparameters (profile ID, transcoding parameters, location, policy ID,policy parameters, etc), as presented in FIG. 3. The proposed RequestTransaction structure supports all the Content types within the scope ofSTI 1.0: images, audio, speech, video, text, presentation formats andcombined media . . . etc.

The Response transaction (response of the Transcoding Platform to theRequest Transaction) contains the Job Results (the Transcoding Jobs'results 1, 2, . . . , N), as presented in FIG. 4. In this Response Body,parameters (duration, return code, etc) either concern the wholeTransaction or the individual Transcoding Jobs' results. For example,the duration corresponds to the complete Transaction duration. Still, inthe job Results, there might also be some parameters describing theparticular transcoding that was performed (i.e. image 1 was transcodedfrom GIF—Graphic Interchange Format—to JPEG—Joint Photographic ExpertsGroup). The proposed interface supports reporting of statistical datagathered during the transcoding at the Job and Transaction levels. TheJob Results contained in the Transaction are detailed in FIG. 5. TheSource block of each Transcoding Job may specify the source type, formatand parameters. The Target block of each Transaction Job has to specifythe desired transcoding parameters and can specify Policy parameters.

The proposed interface also supports transcoding of combined mediaContent, i.e a set of media elements can be transcoded as a whole. Inthis case, it is expected that the Transcoding Platform receives acombined media file, performs combined transcoding of the differencemedia elements (including any logical decisions between the differentmedia elements) and recombines these elements into one transcodedcombined media file as a response. The combined-media is transferred asa MIME-Multipart content item (MIME Part 1 (2, 3, . . . ): seehttp://www.ietf.org/rfc/rfc2045(to2049).txt). The MIME type is eithermultipart/related (in case a presentation exists) or multipart/mixed (incase a presentation does not exist). In the first case, the startparameter refers to the presentation part. FIG. 6 illustrates thestructure of a combined media (with a presentation part). The encodingof the MIME-Multipart (both input and output) is either textual, asdefined in [MIME], or WAP binary encoding, as defined in [WAPWSP](“Wireless Application Protocol, Wireless Session ProtocolSpecification”, WAP-203-WSP-20000504-a, WAP Forum™. URL [UniformResource Locator]=http://www.openmobilealliance.org). The requestedencoding for the target MIME-Multipart is specified in the transcodingparameters of the Transcoding Job. The Content data (either combinedmedia or individual media parts) is referenced from within the SOAPRequest Body (and Response Body), and resides either on a storage thatcan be accessed by the Transcoding Platform or attached as part of theTransaction itself. The proposed interface provides two methods ofsupporting media attachments:

self contained requests, in which the content data reside within theTransaction itself;

references to external Content elements, in which case the Transactiononly contains a pointer to a remote location from where the Contentelements can be pulled by the Transcoding Platform.

Each of the methods will be described below (note that the two optionscan be combined within one Transaction containing references (URLs) toexternal Content elements and attached Content elements). In the casereferences to external Content elements are used, the SOAPRequest/Response Body contains the URLs, pointing to the relevant files,and the Application Platform and the Transcoding Platform have access toa shared persistent storage device, either “local” or accessible viaHTTP or FTP (File Transfer Protocol). In case of self-containedrequests, the SOAP Request/Response Body contains references to theattachments sent along with the Transaction, as MIME parts. Each contentattachment is identified by its MIME Content ID. The SOAPRequest/Response Body refers to the content, using the Content IDs.

The transcoding parameters are the parameters that determine the targetthe Transcoding platform has to create. To specify the transcodingparameters, the Application Platform uses predefined Profiles and/orexplicit transcoding parameters (note that in all cases, the TranscodingPlatform can complement the list of parameters, but one of theTranscoding Platform parameters overrides the parameters that theApplication Platform indicated in the Request Transaction). Thetranscoding parameters can be indicated using a reference to apre-defined Profile (a profile is a set of parameters and constraintsthat define the transcoding target). One common use of a Profile is todescribe the user Equipment (=a device allowing a user access to networkservices) characteristics. The profile reference can then be a referenceto the database that both the Transcoding and Application Platformsshare. In order to use a predefined profile, the Request Transactionspecifies the Profile ID of the profile to be used (the definition of aprofile and its content are out of the scope of the presentdescription). The transcoding parameters can also be indicated using anexplicit list of parameters, which will reflect the characteristics ofthe target device and/or the specific requirements from the Application.When a Profile ID is indicated and explicit parameters are added, theexplicit parameters override the corresponding parameters in thereferenced Profile.

Policy parameters are a mean for the Application Platform to specifygeneral rules (general limitations and preferences) for the RequestTransaction (i.e. priority order between the different media elements, .. . ). To specify the Policy parameters, the Application Platform usespredefined Policy and/or explicit Policy parameters. When a PolicyID isindicated and explicit policy parameters are added, the explicitparameters override the corresponding parameters in the referencedPolicy.

The request transaction will now be explained in detail. As mentionedabove, the Request Transactions contain a SOAP header, made ofTranscoding Jobs, and can contain one or several Content attachments (ifsome Content elements are contained in the Transaction itself). AllContent elements to be transcoded are referenced in the Transcoding Jobs(pointing to an attachment or an external source). The RequestTransaction contains at least one Transcoding Job, and it can containseveral Transcoding Jobs. FIG. 7 shows the structure of a RequestTransaction. Request Transactions that do no contain attachments (allthe files are referenced using a URLs pointing to external sources) havea SOAP header and a SOAP-based Request Body. The SOAP header specifiesthe originating host, the length, the request encoding and the SOAPaction. Request Transactions with Content attachments contain the SOAPheader and a string that will indicate the boundary between each contentattachment, as defined in MIME (see [MIME]). Each Content attachmentcontains its own header (using MIME). Each Content Attachment headercontains its unique ID, its type, its encoding and its length.

According to the invention, the SOAP-based Request Body is structured asindicated in the following Table 1 (in which the structures are writtenin bold): TABLE 1 Mandatory/ parent Name Type Possible Values OptionalComments Transaction Mandatory Several Transcoding Jobs can be sentwithin one request. Transaction TransactionID Integer Mandatory A uniqueID that is given by the Application Platform. TransactionNumTranscodingJobs Integer Optional How many Transcoding Jobs reside inthis Transaction. Transaction Priority Integer 0-2 Optional The priorityof the Transaction (0 is the highest, default is 1) compared to others.Transaction ProfileID String Optional The pre-defined Profile to be usedfor all the Transcoding Jobs within this Transaction. TransactionTranscodingParams Optional The transcoding parameters to be used for allthe Transcoding Jobs within this Transaction. When a predefined Profileis specified and this tag appears, the values specified within this tagoverride the ones in the Profile. Transaction PolicyID String OptionalThe pre-defined policy to be used for the Transaction. TransactionPolicyParams Optional The policy rules to be used for this Transaction.When a predefined Policy is specified and this tag appears, the valuesspecified within this tag override the ones in the Policy. TransactionTranscodingJob Mandatory Each individual transcoding (1 or more)request. TranscodingJob Source Mandatory The source for the TranscodingJob. TranscodingJob Target Mandatory The Target of this Transcoding Job.Source Type String “Combined”, Optional The type of the Source. “Audio”,“Image”, “Video”, “Text”, “SyntheticAudio” Source Format StringAccording to the Optional The format of the Source. supported formatsSource Codec String According to the Optional The codec of the Source.supported codecs Source Location String URL Mandatory The full-path on ashared storage or the Content ID of the attachment Source URLSettingsIDString Optional If any specific settings (headers, passwords, etc.)should be used, in order to access the Source URL, then the ApplicationPlatform SHALL specify a reference to such a set of predefined settingsthrough this parameter. The definition of the set of available settingsis out of the scope of this specification Target ProfileID StringOptional A predefined Profile to use for the Transcoding Job. When aProfileID is defined at the Transaction level and this tag is present atthe Transcoding Job level, the ProfileID at the Transcoding Job leveloverrides the one at the Transaction level. Target TranscodingParamsOptional The transcoding parameters to be used for all the TranscodingJobs within this Transaction. When a predefined Profile is specified andthis tag appears, the values specified within this tag override the onesin the Profile. When TranscodingParams are defined at the Transactionlevel and this tag is present at the Transcoding Job level, theTranscodingParams at the Transcoding Job level override the ones at theTransaction level. Target Location String URL Mandatory The full-path ona shared storage or the Content ID of the attachment. TargetURLSettingsID String Optional If any specific settings (headers,passwords, etc.) should be used, in order to access the Target URL, thenthe Application Platform SHALL specify a reference to such a set ofpredefined settings through this parameter. The definition of the set ofavailable settings is out of the scope of this specification.PolicyParams DeleteOrder Optional Ordered list of media types to bedeleted if necessary. PolicyParams CompressOrder Optional Ordered listof media types to compressed if necessary DeleteOrder MediaType String“Audio”, Optional (1 Media types in order of “Image”, or more) deletion.“Video”, “Text”, “SyntheticAudio”, “Combined” CompressOrder MediaTypeString “Audio”, Optional (1 Media types in order for “Image”, or more)compression. “Video”, “Text”, “SyntheticAudio”, “Combined”TranscodingParams SizeLimit Integer Optional The limit of the file sizesfor the Transaction or the TranscodingJob. Default is unlimited (−1)TranscodingParams Audio Optional The audio transcoding parameters.TranscodingParams Image Optional The image transcoding parameters (alsographics). TranscodingParams Video optional The video transcodingparameters. TranscodingParams Text Optional The text transcodingparameters. TranscodingParams CombinedMedia Optional The combined-mediatranscoding parameters. TranscodingParams Transformation Optional (0transformation that the or more content should go through appearances)Transformation Type String According to the Optional Type oftransformation supported Transformations Transformation parameter StringAccording to the Optional Value of parameter for this SupportedTransformation parameter values for the specific transformation AudioFormat String According to the Optional The file-format of the target.supported audio Any supported audio formats Audio Codec String Accordingto the Optional The desired codec. supported audio Restricted by thefile format codecs Audio BitRate Integer Optional The desired bit-rate.Restricted by the codec Audio SamplingRate Integer Optional The desiredsampling rate. Restricted by the codec Audio SamplingResolution IntegerOptional The desired sampling resolution. Restricted by the codec AudioSynthetic Optional Synthetic audio related parameters. SyntheticChannelToUse Integer Optional Number of input channel to be used in casethe output contains only one channel. Synthetic ChannelsPriority StringOptional A comma separated permutation of 0-15. The priority of thechannels, from the most important to the least important. Default is0-15. Synthetic Instrument Integer Optional The instrument to use, whentranscoding to midi. Irrelevant for other formats, default is pianoAudio SizeLimit Integer Optional The limit of the file size for anaudio. Default is unimited (−1) Image Format String According to theOptional The format of the target. supported image Any supported imageformats Image ColorScheme String “True24Bit”, Optional The desired colorscheme “True12Bit”, “Palette256Co”, “Palette256Gr”, “Palette32Co”,“Palette32Gr”, “Palette16Co”, “Palette16Gr”, “Palette4Co”, “Palette4Gr”,“1Bit” Image Width Integer Optional The target width. The default is theoriginal width. Image Height Integer Optional The target height. Thedefault is the original heig Image Resize String “AspectRatio”, OptionalMaintain the aspect ratio Policy “Crop”, “None” when resizing (the newdimensions are set to fit into the desired width while aspect ratio ismaintained), crop when shrinking (do not scale the image - take itscentral rectangle), or just stretch. Image SizeLimit Integer OptionalSize limit for the image. Default is unlimited (−1) Video Format StringAccording to the Optional The format of the target. supported video Anysupported video formats Video Codec String According to the Optional Thevideo codec of the supported video target. codecs Video Width IntegerOptional Target width Video Height Integer Optional Target height VideoFrameRate Integer Optional The wanted target frame rate Video BitRateInteger Optional The desired target bit rate Video Audio Optional Audioparameters. Video SizeLimit Integer Optional Size limit for the Audio.Default is unlimited (−1) CombinedMedia SizeLimit Integer Optional Sizelimit for the whole combined media. Default is unlimited (−1)CombinedMedia PresentationParams Optional Parameters for the targetpresentation. PresentationParams Format String “SMIL”, Optional Targetpresentation format “HTML”, “None” PresentationParams Template StringOptional Template for presentation to be used in case of presentationformat change. This is either a URL, or a content ID of the attachmentPresentationParams Layout String “Portrait”, Optional Target layout.“Landscape” Default is the source layout. CombinedMedia Encoding String“Textual”, Optional The encoding of the output “WAP” MIME-Multipart.Default is textual. CombinedMedia TranscodingParams Optional TranscodingParameters for media-elements inside the combined-media (more than onemedia type may be specifled here). The Parameters are specified for allthe content-elements of the same type. For example, in order totranscode a video to a combined-media (e.g. image/s + audio +presentation), the target Parameters for the audio, image, andpresentation are specified here. CombinedMedia OverallParams OptionalLimitations on media parameters in the combined- media. OverallParamsWidth Integer Optional Target width OverallParams Height IntegerOptional Target height OverallParams BitsPerPixel Integer OptionalSupported Number of bits per pixel OverallParams AllowColor BooleanOptional Indication whether color images are allowed as an output.OverallParams MaxImageWidth Integer Optional Maximum width allowed forimage. OverallParams MaxImageHeight Integer Optional Maximum heightallowed for an image. OverallParams AllowImage Boolean OptionalIndication whether output can contain image. OverallParams AllowAudioBoolean Optional Indication whether output can contain audio.OverallParams AllowVideo Boolean Optional Indication whether output cancontain video OverallParams SupportedContentTypes Optional A list of thesupported content types. SupportedContentTypes Type String Optional Asingle content type 1 or more)

In order to perform transformations on the media, the ApplicationPlatform specifies, for each requested transformation, the type of thetransformation and the parameter for the transformation. The followingTable 2 lists the minimal set of supported transformations, the allowedparameter values for these transformations, and the type (or types) ofmedia elements on which these transformations may be used. STI supportsother proprietary Transformations that will then have to be definedbetween the Application Platform and the Transcoding Platform. If theTranscoding Platform does not recognize the Transformation type, itreturns an error. TABLE 2 Transformation Type Possible parameter valuesMedia Types Description LevelCorrection No parameter Image Perform levelcorrection. Mirror “UD”, “LR, Image “UD” - vertical mirror, “LR” -“Diagonal”, horizontal mirror. Default is “None” “None”. NoiseReductionNo parameter Image Perform noise reduction. Rotation Angle of clockwiseImage Perform Image rotation rotation (0-359) Sharpen No parameter ImagePerform image sharpening. DurationLimit Limit on duration (in Video,Audio, Truncate the media if its duration milliseconds) CombinedMedia(e.g. exceeds this limit. for slideshow) AGC No parameter Audio PerformAutomatic Gain Control Offset Offset in source media Audio, Video thesource image to start the (in Transcoding from. milliseconds)AudioChannels “Mono”, “Stereo”, Audio Change the number of channels“DualMono”, in the output. “IntensityStereo” FrameRateSample New framerate Image (e.g. for Change the frame sampling rate slideshow) (withoutchanging the speed and the duration of the media) FrameRateOutput Newframe rate Image (e.g. for Change the frame rate in the slideshow)output (and thus change also the speed and the duration of the media).NumberOfFrames New number of frames Image (e.g. for Change the number offrames in slideshow) the output.

A request Transaction is considered as successful unless there was anerror during the handling of the transaction that prevented thecompletion of the whole Transaction. Errors in specific Transcoding Jobsdo not affect the success value of the entire Request Transaction. Thatis, a Request Transaction may be successful even though some (or all) ofthe Transcoding Jobs failed. The structure of a successful ResponseTransaction, containing the results of one or more Transcoding Jobs, isquite similar to the Request Transaction, i.e. a SOAP header, includinga success code, and one or more Job Results and optionally the Contentattachments. The Response Body contains references to either externalcontent element or self-contained content elements. The same differencesbetween a Transaction with contained content elements and withoutcontained content elements, as discussed in the Request Transaction,apply for Response Transactions. FIG. 8 shows the structure of theResponse Transaction. As for the Request Body, a table indicates (Table3) how the Response Body is structured: TABLE 3 Parent Name TypePossible values Comments Transaction The response Transaction ReturnCodeInteger The return code of the Transaction (either a successful or awarning) Transaction NumJobResults Integer How many Job Results residuein this response. Transaction ProfileID String The Profile ID that wasused for this transaction (in case it was specified in the Transactionblock of the request) Transaction PolicyID String The Policy ID that wasused for this transaction (in case it was specified in the Transactionblock of the request) Transaction TransactionID Integer The unique IDthat was received from the Application Platform in the requestTransaction ContextID Integer A unique ID of the transcoding sessionthat is given by the Transcoding Platform. Transaction TotalDurationInteger The time it took the Transcoding Platform to perform the entiretranscoding Transaction in milliseconds. This number is the duration ofthe whole transaction from the time it reached the Transcoding Platformto the time the response was sent (it can be higher or lower the sum ofdurations for all the Job Results). Transaction JobResult The JobResults. May be more than one (one per each Transcoding Job) JobResultReturnCode Integer The return code of the Transcoding Job (either asuccessful or a warning) JobResult Message String A message with anexplanation in case of a warning JobResult Duration Integer The durationit took this Transcoding Job (in milliseconds) JobResult Target Detailsabout the target. Target FileSize Integer The actual size of the fileTarget Location String The full-path on a shared storage or the ContentID of the attachment. Target ProfileID String The Profile ID that wasused for this Transcoding Job (in case it was specified). TargetTranscodingParams The Transcoding Parameters of the target.TranscodingParams SizeLimit Integer The limit that was given to theentire transaction TranscodingParams Audio Audio detailsTranscodingParams Image Image details TranscodingParams Video Videodetails TranscodingParams Text Text details TranscodingParamsCombinedMedia Combined-media details TranscodingParams Transformation ATransformation that was applied (0 or more appearances). TransformationType String According to the Type of transformation supportedTransformations Transformation Parameter String According to the Valueof parameter for Supported this transformation parameter values for thespecific transformation Audio Format String The supported The fileformat audio formats Audio Codec String The supported The codec audiocodecs Audio BitRate Integer The bit-rate Audio SamplingRate Integer Thesampling rate Audio SamplingResolution Integer The sampling resolutionAudio SizeLimit Integer The limit that was given for an audio AudioSynthetic Optional Synthetic audio related parameters. SyntheticChannelToUse Integer Optional Number of input channel used in case theoutput contains only one channel. Synthetic ChannelsPriority StringOptional A comma separated permutation of 0-15. The priority of thechannels, from the most important to the least important. SyntheticInstrument Integer Optional The instrument used, when transcoding tomidi. Irrelevant for other formats. Image Format String The supportedThe format image formats Image ColorScheme String “True24Bit”, The colorscheme of the “True12Bit”, image “Palette256Co”, “Palette256Gr”,“Palette32Co”, “Palette32Gr”, “Palette16Co”, “Pallete16Gr”,“Palette4Co”, “Palette4Gr”, “1Bit” Image NunberOfColors Integer Theactual number of colors Image Width Integer The width Image HeightInteger The height Image SizeLimit Integer The limit that was given foran image Video Format String The supported The format video formatsVideo Codec String The supported The codec video codecs Video WidthInteger The width Video Height Integer The height Video FrameRateInteger The frame rate Video BitRate Integer The bit rate VideoSizeLimit Integer The limit that was given for a video CombinedMediaSizeLimit Integer The limit that was given for a combined-mediaCombinedMedia PresentationParams Parameters for the target presentationtranscoding. PresentationParams Format String “SMIL”, Targetpresentation “HTML”, format “None” PresentationParams Template StringTemplate for presentation that was used. PresentationParams LayoutString “Portrait”, Target layout. “Landscape” CombinedMedia EncodingString “Textual”, The encoding of the “WAP” output MIME-Multipart.

A Transaction Failure response is returned in a situation where thewhole Transaction could not be handled. This may happen if there was aproblem with the Transaction parameters, or any other problem, whichrelates to the whole Transaction (and not only to one or more of theTranscoding Jobs). The header of a Transcoding error contains a linethat indicates that there was an error (HTTP/1.1 500 Error), and theregular fields. The body of the SOAP, of a different structure from asuccessful one, is given in Table 4 below: TABLE 4 Parent Name TypePossible values Description FaultResponse The fault FaultResponseTransactionID Integer The unique ID that was received from theApplication Platform in the request FaultResponse ContextID Integer Aunique ID of the transcoding session that is given by the Transcodingplatform FaultResponse TotalDuration Integer The total milliseconds ittook the whole Transaction to be handled (until the error occurred)FaultResponse ReturnCode Integer Out of the possible error codesFaultResponse Message String An explanatory error message

It may be added that the Transcoding Platform supports the Transactionerror codes indicated in the following Table 5: TABLE 5 Error code Errorstring 1001 Parsing error 1004 Erroneous target structure 1005 Error intarget data 1006 General server error 1008 No media detected in requestmessage 1009 Response composition error (<err-code>) 1010 Number ofconcurrent requests exceeded the maximum 1011 Erroneous transcodingrequest 1012 Transaction result exceed maximal size 1013 Policy couldnot be accomplished and transaction failed. 1014 Policy could not beaccomplished but transaction succeeded.

and that Transcoding Platform supports the Transcoding Job error codesindicated in the following Table 6: TABLE 6 Error code Error string 2001Error in input media 2002 Unsupported Content Type 2003 UnsupportedContent Format 2004 Unsupported Content Codec 2005 Unsupported Content2006 Unsupported transcoding request 2006 Unsupported Transformation2007 No media detected in request message 2008 Output content sizeexceeds the limit 2009 Failed to read source content. 2010 Failed towrite target content. 2101 DRM protected content: no transcoding done

1. A transcoding system comprising an application platform and atranscoding platform for executing transcoding transactions thatcomprise the following steps: transmission of a request from saidapplication platform to said transcoding platform, execution of saidrequest by said transcoding platform, transmission of a response fromsaid transcoding platform to said application platform, wherein saidrequest is based on a request body which is structured as indicated inTable 1, and said response, when successful, is based on a response bodywhich is structured as indicated in Table
 3. 2. A transcoding system asclaimed in claim 1, wherein said request has a transcoding parameterelement comprising a transformation element that defines atransformation through which a content must go, amongst a plurality ofsupported transformations as defined in Table
 2. 3. A device hosting anapplication platform for use in a transcoding system as claimed inclaim
 1. 4. A device hosting a transcoding platform for use in atranscoding system as claimed in claim
 1. 5. A request having the formatdescribed in Table 1 of a transcoding system as defined in claim
 1. 6. Arequest having a transcoding parameter element comprising atransformation element that defines a transformation through which acontent must go, amongst a plurality of supported transformations asdefined in Table 3 of a transcoding system as defined in claim
 2. 7. Aresponse having the format described in Table 2 of a transcoding systemas defined in claim 1.